INTERPRETATION OF ROAD ROUGHNESS PROFILE DATA

Abstract

majority of States own high-speed devices for measuring longitudinal road profiles that are potentially rich in information about the pavement surface condition. primary objective of this research was to advance the state of practice for extracting this information. A secondary objective was to assist users in resolving common measurement errors. Vast amounts of measured profile data were acquired to evaluate various analysis methods in terms of their usefulness and validity when applied to profiles obtained from different types of instruments. Methods for determining an index called Rideability Number (RN) were studied in detail. A practical algorithm was developed for computing RN without bias from profiles obtained from a variety of equipment, with the exception of those that use ultrasonic sensors. Other analyses studied in the project include the International Roughness Index (IRI), power spectral density (PSD), high-pass filters, and cross correlation. research was coordinated with activities of the Road Profiler User Group (RPUG). A critical problem facing road profiler users is a lack of knowledge involving the technology. Accordingly, a 2 1/2 day course on profile measurement and analysis was prepared, along with the first draft of a companion document called The Little Book of Profiling. course introduces new users to the basics of what profilers are, how they work, and what can be done with their data. A user-friendly profile analysis software package called RoadRuf was developed that includes many profile analysis methods. software had been provided to participating States, and is available on the Internet.